Liquid waste burner

ABSTRACT

A system for burning waste lubricating oil along with regular fuel oil in a conventional heating burner. The waste oil is supplied only after the burner has thoroughly heated up on burning regular fuel oil. A snorkel device is provided to assure that only liquids and no solids are drawn into the system. A constant displacement pump in the waste oil flow path serves the purpose of adjusting the ratio of regular fuel to waste oil. The waste oil is supplied directly to the swirl chamber of the burner nozzle.

United States Patent Kramer et al.

1451 Apr. 16, 1974 LIQUID WASTE BURNER Inventors: William E. Kramer,Pittsburgh;

John Scarr, Verona, both of Pa.

Assignee: Gulf Research & Development Company, Pittsburgh, Pa.

Filed: Oct. 16, 1972 Appl. No.: 297,587

US. Cl 239/124, 239/406, 431/6 Int. Cl BOSb 1/34 Field of Search 239/5,403, 405, 406, 422,

3,246,853 4/1966 Biber et al. 239/403 3,286,997 11/1966 Ledbetter239/403 X 3,443,760 5/1969 Simmons 239/403 X Primary Examiner-M. HensonWood, Jr. Assistant ExaminerMichael Y. Mar

[ 5 7 ABSTRACT A system for burning waste lubricating oil along withregular fuel oil in a conventional heating burner. The waste oil issupplied only after the burner has thoroughly heated up on burningregular fuel oil. A snorkel device is provided to assure that onlyliquids and no solids are drawn into the system. A constant displacementpump in the waste oil flow path serves the purpose of adjusting theratio of regular fuel to waste oil. The waste oil is supplied directlyto the swirl chamber of the burner nozzle.

4 Claims, 3 Drawing Figures 1111mm 1 i H PATENTED 51974 7 3, 804,333

4 RELIEF 22 20 VALVE a 5o 52 46 so as 64 7o s4 62 as 12 1: 48

l I I I I i 78 v THERMOSTAT DELAY 94 SOLENOID IGNITION z m f VALVELIQUID WASTE BURNER This invention pertains to methods and apparatus fordisposing of combustible liquid wastes, such as spent lubricating oil,by incineration.

Generally, the invention is useful wherever it is necessary to disposeof any combustible liquid, such as, for example, spent quenching oils,waste cutting fluids, waste industrial lubricants, and the like. Theinvention was particularly developed for use in retail gasoline servicestations wherein the accumulation of spent lubricating oil, such as isdrained from automotive crankcases, becomes a problem in that largeamounts are accumulated in the station. Thus, a primary object of theinvention is the provision of means of incinerating such crankcase oilthereby relieving the service station operator from the burden ofotherwise disposing of it.

The general approach of the invention is to provide a system wherein thewaste oil or other combustible liquid can be burned, cleanly, along withregular fuel oil in the service stations heating system, so as tothereby not only dispose of the waste oil, but to additionally derivebenefits from it, i.e., to derive whatever heating value the waste oilmay contain. Another advantage of the invention is that it provides forseparate storage of the waste fluid and the regular fuel oil, and causesthem to mix together in the swirl chamber of the nozzle in the oilburner. In prior systems, wherein the two fluids are premixed,additional problems arise, including the need for frequent checking tokeep the concentration of the blend within set limits to assure reliableignition and combustion; entrainment of pollutants and solidcontaminants which can cause nozzle plugging; and erratic flow ratescaused by variations in the viscosity of the blend.

The invention allows the fire to be started with regular fuel oil onlyby providing time delay means before beginning the flow of waste oil tothe nozzle swirl chamber. This feature provides the advantage that theburner apparatus is thoroughly warmed up on a regular fuel oil fire onlybefore the waste oil begins to flow, thus assuring efficientincineration of the waste oil. Further, this system assures the stationwill be properly heated even if there is no waste oil to burn.

The invention also provides a modified standard nozzle having meanstherein to permit the burning of two fuels and to cause mixing of thesetwo fuels in the nozzle swirl chamber only, while at the same timeproviding check means to assure that the regular fuel oil does not enterthe waste oil system. That is, means ar provided to assure that theregular fuel oil is not contaminated with the waste oil until the twoare mixed in the swirl chamber of the nozzle.

Since the waste oil does not flow through the nozzle slots, there isless tendency for the nozzle to clog and less tendency for the flow rateto change due to variations in fluid viscosity. The atomization of onlyregular fuel oil at start-up assures reliable ignition and goodcombustion performance independent of the physical properties of thewaste oil.

The above and other advantages of the invention will become evident inthe following detailed description and claims, and in the accompanyingdrawing also forming a part of the disclosure in which:

FIG. 1 is a general schematic view of a system embodying the invention;

FIG. 2 is cross-sectional view through the nozzle of FIG. 1; and

FIG. 3 is an electrical schematic diagram of the circuit portion of thesystem shown in FIG. 1.

Referring now to FIG. 1, reference numeral 10 designates the systemgenerally, and system 10 comprises any conventional pressure atomizinggun type oil burner 12. The regular fuel oil to be burned in burner 12is supplied in a conduit 14 from a conventional tank or other source ofsupply, not shown. A nozzle and adapter assembly 16 is housed within theburner 12 adjacent to the outlet end thereof, in the usual manner. Thewaste oil to be burned is supplied to nozzle 16 via a conduit 18.Conduit 18 includes, in series, moving away from burner 12, a delayedopening solenoid valve 20, a filter 22, and terminates at one leg of afour-way junction 24.

A pressure gauge 26 is positioned off of a second leg ofjunction 24, anda pair of conduits 28 and 30 extend from the remaining two legs of thisjunction 24. Conduit 28 includes only a pressure relief valve 32 andthis line 28 terminates at one leg ofa three-way junction 34. Conduit 30extends between the junctions 24 and 34, and it includes an adjustableoutput constant displacement pump 36, indicated by the legend C.D. Pumpon the drawing, a vacuum gauge 38, and another filter or strainer 40.

A line or conduit 42 extends from the remaining leg of three-wayjunction 34 to a tank 44 used to store the waste liquid to beincinerated in burner 12. Positioned in tank 44 is a snorkel device 46to which the conduit 42 attaches. Device 46 is provided to assure thatthe waste fuel will be taken off of the top of the liquid level in thetank 44, to thereby enhance the settling out of solid particles. Thesnorkel protects the remaining system by reducing the possibility ofsolid particles being drawn into the system by pump 36 and fouling thevarious components.

All of the parts shown in FIGS. 1 and 3, with exception of the nozzleand adapter assembly 16, are standard off-the-shelf components and thusneed not be described in any further detail herein. As an alternativearrangement, pump 36 and valve 32 could be replaced by a standard oilburner fuel unit having a built-in relief valve and constant pressureflow valve.

Referring now to FIG. 2, the nozzle and adapter assembly 16 is shown inmore detail, and comprises an adapter body 46 having a nozzle housing 48secured to its front end by suitable interacting threads. The nozzle isessentially the one of U. S. Pat. No. 3,272,441 by O. A. Davis, Sr. andER. Walsh, and assigned to the same assignee as the present invention.

Adapter body 46 has thread means 50 at its rear end to which-the regularfuel oil conduit 14 is connected. The regular fuel oil passes through apassageway 52 in adapter body 46, and exits into a main chamber 54.Conduit 18 carrying the waste oil or other combustible liquid to beincinerated terminates at a block 56 which connects into a side opening58 in adapter body 46. Side opening 58 connects to a central opening 60which communicates with a stepped down portion of main chamber 54.Positioned within chamber 54 is a central nozzle member having a rearstud portion 64 which fits within the stepped down portion of chamber 54described above. O-Ring 66 is fitted in a suitably formed groove in thestud portion 64 and forms a seal at this location between the regularfuel oil and the waste oil systems. Member 62 is formed with a throughcentral passageway 68 for the waste oil from conduit 18. At its frontend, central passageway 68 is enlarged as at 72, and this enlargedportion carries a ball cheek member 74 which is urged by a spring 76towards a position to close passageway 68 from passageway 72. At thefront end of enlarged portion 72, the nozzle includes a swirl pin 78.The spring 76 has its front end bearing against the rear surface of thisswirl pin 78. On its outside surface, member 62 is formed with aplurality of slots 70 which form the passageways for the regular fueloil to enter chamber 55 from chamber 54.

Swirl pin 78 is formed with a central passageway 80 which flows thewaste oil passing therethrough to the swirl chamber 82 in the nozzle.The swirl pin is similar to that described in the above-identifiedUnited States Patent, particularly in FIG. 8 thereof, and comprises aplurality of swirl slots 84, but need not be described in any furtherdetail herein. Other nozzles could be used, the criterion is that thewaste oil be mixed with the regular fuel oil as late as possible, theswirl chamber 82 or equivalent being about the extreme limit of thisdeseratum. Nozzle housing 48 comprises a rear boss 86 which is threadedon both its inside and outside surfaces to serve to interconnect adapterbody 46 with threaded portions 71 on the central nozzle member 62. Theslots 70 in the central member described above define portions 71,making them into so-called split threads. Such portions 71 are typicallyprovided. At its front end, nozzle housing 48 comprises a central exitopening 88 from which the combination of the thoroughly mixed two fuelsleave the nozzle and enter the combustion area in a finely atomizedspray. Slightly rearwardly of this opening 88, housing 48 is formed witha circle of air aspirating openings 90, as described in theaforementioned patent. At the forward inside end of the nozzle housing,there is provided an orifice disc 92, on the inside surface of which theswirl pin 78 is positioned. The space behind the orifice disc andforward of the front face of the swirl pin defines the swirl chamber 82.

Generally, the regular fuel oil under pressure swirls through the swirlchamber 82 forming a thin film therein, and thereafter, as will beexplained below, the waste oil is supplied to the central passageway 80into the swirl chamber 82. Thus, mixing of the waste and regular fueloils occurs only in the swirl chamber 82 and not earlier, therebyachieving the advantages of no premixing, and others as mentioned above.

Referring now to FIG. 3, there is shown a schematic diagram of theelectrical portion of the invention, which is extremely simple, and manyother similar and well-known circuits could be used. By way of example,there is shown a thermostat 94 connected to a primary control circuit 96of any suitable conventional design. Circuit 96, as is known to thoseskilled in the art, will include a transformer, a relay, safety means,and the like, all of which need not be shown. A pair of lines 98 and 100extend out of the primary control 96, and the remaining devices arewired in parallel across the lines 98 and 100. These devices includeignition means 102, the motor 104 in the gun burner 12, the pump 36 forthe waste oil, and the delay opening solenoid valve 20.

OPERATION In operation, the thermostat 94 signals when heat is needed.This signal, via primary control 96, immediately activates lines 98 and100 to cause the burner motor and the ignition means 102, not otherwiseshown, to start immediately thereby causing the fire to start up onregular fuel oil only. The constant displacement pump 36 alsoimmediately starts to operate, but because valve 20-is still closed andwill remain closed for its inherent time delay, the waste oil cyclesaround the conduits 30 and 28 and the junctions 24 and 34 until thisvalve times out" and thereafter opens, then allowing waste oil to be fedto the nozzle. A constant displacement pump is used at 36 for itsaccurate delivery control capability, whereby the ratio of regular fuelto waste oil supplied to the nozzle can be accurately controlled.

Pressure gauge 26 is used to indicate changes in resistance to flow tothe nozzle. Vacuum gauge 38 serves to indicate the extent of filterplugging. With delay valve 20 closed and pump 36 running, there must berelief of pressure by the opening of relief valve 32 or the pump willstall or break.

With regular fuel oil supplied to the nozzle at a typical pressure ofpsi obtained from the burner fuel pump, not shown, a constant desiredfuel flow rate for start-up is assured. When waste oil is introduced tothe nozzle, total flow is approximately equal to the sum of both flowrates. There may be a slight fall off of regular fuel flow depending onthe amount of waste oil added and its effect on nozzle flow resistance.

For example, as nozzle flow resistance goes up due to an increase in oilmix viscosity, the pressure regulating relief valve of the burner fuelpump will open wider to maintain the given nozzle pressure, thus, therewill be some drop in regular fuel flow.

The waste oil bypass feature has several advantages. Primarily, itallows the burner 12 to warm up on regular fuel oil only. Further, thisfeature allows the waste oil to be warmed up" by flowing through thebypass system before being allowed to pass through the nozzle, therebymaking the waste oil less viscous and more flowable, while alsosubjecting the waste oil to refiltration. The bypass assures dependablestarts with good atomization and ignition of the regular fuel; lessfilter plugging, minimum viscosity effects, and therefore a more nearlyconstant flow rate.

The filters 22 and 40 are provided as a safety means to protect the pump36 and the nozzle assembly 16, respectively, from contamination. It isanticipated that the waste liquid in tank 44 will be quite dirty.

As mentioned above, virtually all the components are standard items ofcommerce. In the successfully constructed embodiment the key componentswere:

c. obround tank Thermostat 94 Robertshaw CM-260 low voltage Controls Co.switch Primary Honeywell Cn. R 8 l 84 constant igni- Control 96 tion,cad-cell flame detector In this successfully constructed embodiment,valve 20 was set for a delay of about eight seconds. This feature isadjustable dependent upon the regular fuel supply and the waste liquidto be burned.

While the invention has been described in detail above, it is to beunderstood that this detailed description is by way of example only, andthe protection granted is to be limited only within the spirit of theinvention and the scope of the following claims.

We claim:

1. A system for burning two liquids in a single burner apparatuscomprising a burner apparatus, means to supply a first liquid to theburner apparatus, means to supply a second liquid to said burnerapparatus, said supply means for said second liquid including time delaymeans whereby the burner apparatus begins operation with said firstliquid and thereafter continues operation with both said first liquidand said second liquid, said burner apparatus comprising a nozzle havinga swirl chamber therein, means to bring said first and second liquidstogether in said swirl chamber, and spring loaded ball check valve meansto permit the flow of said second liquid into said swirl chamber and toprevent the flow of said first liquid into the portions of said nozzlewhich carry said second liquid.

2. A system for burning two liquids in a single burner apparatuscomprising means to supply a first liquid to the burner apparatus, meansto supply a second liquid to said burner apparatus, and said supplymeans for said second liquid are adapted to begin operation with saidfirst liquid and thereafter continue operation with both said firstliquid and said second liquid and comprise a tank for said secondliquid, a delay solenoid valve which controls the flow of said secondliquid from said tank to said burner apparatus, a pump connected inseries between the tank and delay solenoid valve, a bypass loopconnected into the supply means for said second liquid between the pumpand delay solenoid valve, whereby said pump and said burner apparatusmay be started at the same time and said second liquid flows around saidbypass loop until said delayed opening solenoid valve times out andpermits said second liquid to flow to said burner apparatus.

3. The combination of claim 2, said pump comprising an adjustableconstant displacement pump, whereby the ratio of said first and secondliquids supplied to said burner apparatus may be accurately controlled.

4. A system for burning a fuel and a combustible waste liquid in asingle burner apparatus comprising a burner body having an exit end, anexit opening centrally positioned at said exit end, a central wasteliquid passage extending through the burner body to the exit endthereof, a swirl pin closing the exit end of the central waste liquidpassage, said swirl pin having a centrally located flat exit end and aconical surface extending from the periphery of the flat exit end awayfrom the exit end of the burner body, a central duct through the swirlpin communicating with the central passage, an orifice disc having acentral opening adjacent to the central exit opening and a concaveconical surface adapted to fit against the conical surface of the swirlpin, a swirl chamber between the flat exit end of the swirl pin and theconical surface of the orifice disc, angularly oriented grooves in theconical surface of the swirl pin extending from the periphery thereof tothe swirl chamber, an annular fuel chamber communicating with the endsof the grooves remote from the swirl chamber, air aspirating passagesthrough the burner body opening into the space between the central exitopening and the opening in the orifice disc, pumping means fordelivering the combustible waste liquid to the central passage, andmeans for delivering fuel to the annular fuel chamber,

1. A system for burning two liquids in a single burner apparatuscomprising a burner apparatus, means to supply a first liquid to theburner apparatus, means to supply a second liquid to said burnerapparatus, said supply means for said second liquid including time delaymeans whereby the burner apparatus begins operation with said firstliquid and thereafter continues operation with both said firSt liquidand said second liquid, said burner apparatus comprising a nozzle havinga swirl chamber therein, means to bring said first and second liquidstogether in said swirl chamber, and spring loaded ball check valve meansto permit the flow of said second liquid into said swirl chamber and toprevent the flow of said first liquid into the portions of said nozzlewhich carry said second liquid.
 2. A system for burning two liquids in asingle burner apparatus comprising means to supply a first liquid to theburner apparatus, means to supply a second liquid to said burnerapparatus, and said supply means for said second liquid are adapted tobegin operation with said first liquid and thereafter continue operationwith both said first liquid and said second liquid and comprise a tankfor said second liquid, a delay solenoid valve which controls the flowof said second liquid from said tank to said burner apparatus, a pumpconnected in series between the tank and delay solenoid valve, a bypassloop connected into the supply means for said second liquid between thepump and delay solenoid valve, whereby said pump and said burnerapparatus may be started at the same time and said second liquid flowsaround said bypass loop until said delayed opening solenoid valve timesout and permits said second liquid to flow to said burner apparatus. 3.The combination of claim 2, said pump comprising an adjustable constantdisplacement pump, whereby the ratio of said first and second liquidssupplied to said burner apparatus may be accurately controlled.
 4. Asystem for burning a fuel and a combustible waste liquid in a singleburner apparatus comprising a burner body having an exit end, an exitopening centrally positioned at said exit end, a central waste liquidpassage extending through the burner body to the exit end thereof, aswirl pin closing the exit end of the central waste liquid passage, saidswirl pin having a centrally located flat exit end and a conical surfaceextending from the periphery of the flat exit end away from the exit endof the burner body, a central duct through the swirl pin communicatingwith the central passage, an orifice disc having a central openingadjacent to the central exit opening and a concave conical surfaceadapted to fit against the conical surface of the swirl pin, a swirlchamber between the flat exit end of the swirl pin and the conicalsurface of the orifice disc, angularly oriented grooves in the conicalsurface of the swirl pin extending from the periphery thereof to theswirl chamber, an annular fuel chamber communicating with the ends ofthe grooves remote from the swirl chamber, air aspirating passagesthrough the burner body opening into the space between the central exitopening and the opening in the orifice disc, pumping means fordelivering the combustible waste liquid to the central passage, andmeans for delivering fuel to the annular fuel chamber.